1. Field of the Invention
The present invention relates to a Zigbee device and a method for management of a Zigbee device.
2. Description of the Related Art
Recently, various types of wireless communications have be utilized everywhere in real life due to the development of communication technology.
Such wireless communication technologies have been established as global standards in various types such as a mobile phone, a wireless Ian, a Bluetooth, a Zigbee or the like and they are used in optimum fields respectively according to features.
Herein, the Zigbee means one of IEEE 802.15.4 standards to support a near field communication and it is used in various fields such as an intelligent home network, a near field communication market for buildings, an industrial automation, logistics, environment monitoring, an human interface, telematics, military fields or the like.
Since Zigbee networks have devices being relatively small, the power consumption thereof is low and the manufacturing cost of the devices used in Zigbee networking is cheap in comparison with the other network methods, they have been in the spotlight recently as Ubiquitous construction solutions such as a home network.
On the other hand, as interests for smart energy 2.0 have been increased, the smart energy 2.0 is implemented through a protocol as a Zigbee IP stack as shown in FIG. 1.
Referring to FIG. 1, a link layer plays roles of discovering PANs(Personal Area Networks) within a communication range and transmitting a data frame consisting of a payload of maximum approximately 100 bytes.
An adaptation layer plays roles of performing compression and depression and performing fragmentation and reassembly of IPv6 packet exceeding the maximum payload of the link layer frame.
A network layer performs the functions of routing, IPv6 addressing and packet forming.
On the other hand, since a MTU(Maximum Transmission Unit) is 1280 bytes, it is transceived by performing fragmentation into the maximum 102 bytes, therefore, there is required for a buffer in order to process this.
FIG. 2 is an exemplary diagram schematically showing a flow to process a data frame in the Zigbee IP stack.
Referring to FIG. 2, a source node requires a transmission buffer of minimum 1,280 bytes in order that the source node transmits a frame of 1,280 bytes to a destination node and the destination node requires a transmission buffer of minimum 1,280 bytes in order to process by receiving this. And also, a medium router requires a buffer having an approximate size in order to relay this.
On the other hand, although there is no problem if another frame is received under the condition that the buffer is empty by allowing the received data frame to be processed in such procedure, there is frequently occurred that another received data frame is stored in the buffer before the received data frame is processed.
As FIG. 3 is an exemplary view schematically showing a Zigbee IP network, referring to FIG. 3, in case when a plurality of routers 20 or hosts continuously transmit data frames to one edge router, the data which is larger than an amount of data capable of being processed by the edge router to receive this may be received, in this result, there may occur a frame drop phenomenon since the buffer is fully occupied.
Of course, although the above-described problem is overcome by increasing a basic buffer size, but in this case there is a problem to raise a manufacturing cost.
On the other hand, in the patent reference 1, there is disclosed a method to avoid a local congestion in a wireless personal region network, the invention disclosed in the patent reference 1 is a major object to perform a congestion control by using a reserved field, although it can additionally prevent a bottleneck phenomenon which the buffering of node is overflow, but there is a limit that a fundamental solution is not still found to solve a deficiency state of buffers to be predicted as being frequently generated in the smart energy 2.0 or the like.